415 research outputs found
Source levels of social sounds in migrating humpback whales (Megaptera novaeangliae)
The source level of an animal sound is important in communication, since it affects the distance over which the sound is audible. Several measurements of source levels of whale sounds have been reported, but the accuracy of many is limited because the distance to the source and the acoustic transmission loss were estimated rather than measured. This paper presents measurements of source levels of social sounds (surface-generated and vocal sounds) of humpback whales from a sample of 998 sounds recorded from 49 migrating humpback whale groups. Sources were localized using a wide baseline five hydrophone array and transmission loss was measured for the site. Social vocalization source levels were found to range from 123 to 183 dB re 1 mu Pa @ 1 m with a median of 158 dB re 1 mu Pa @ 1 m. Source levels of surface-generated social sounds ("breaches" and "slaps") were narrower in range (133 to 171 dB re 1 mu Pa @ 1 m) but slightly higher in level (median of 162 dB re 1 mu Pa @ 1 m) compared to vocalizations. The data suggest that group composition has an effect on group vocalization source levels in that singletons and mother-calf-singing escort groups tend to vocalize at higher levels compared to other group compositions. VC 2013 Acoustical Society of America
Novel Assay of Metformin Levels in Patients With Type 2 Diabetes and Varying Levels of Renal Function: Clinical recommendations
AbstractObjective: To study trough levels of metformin in serum and its intra individual variation in patients using a newly developed assay. Research Design and Methods: Trough serum levels of metformin was measured once using Liquid Chromatography Tandem Mass Spectrometry (LcMSMS) in 137 type 2 diabetes patients with varying renal function (99 men) and followed repeatedly during two months in 20 patients (16 men) with estimated GFR (eGFR) below 60 ml/min/1.73 m(2) body surface. Results: Patients with eGFR >60, 30-60, and <30 ml/min/1.73 m(2) had a median trough metformin concentration of 4.5 mumol/l (range 0.1-20.7, n=107), 7.71 mumol/l (0.12-15.15, n=21), and 8.88 mumol/l (5.99-18.60, n=9), respectively. The median intraindividual overall coefficient of variation (CV) was 29.4 % (range 9,8-74,2). Conclusions: Determination of serum metformin with the LCMSMS technique is useful in patients on metformin treatment. Few patients had values over 20 mumol/L. Metformin measurement is less suitable for dose titration
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Managing ‘academic value’: the 360-degree perspective
The raison d'etre of all universities is to create and deliver ‘academic value’, which we define as the sum total of the contributions from the 360-degree ‘angles’ of the academic community, including all categories of staff, as well as external stakeholders (e.g. regulatory, commercial, professional and community interests). As a way to conceptualise these complex relationships, we present the ‘academic wheel’ to illustrate the structural nature of them. We then discuss the implications of the different – and sometimes difficult – perspectives of academic, professional and administrative groups in the context of a number of important social psychological processes. We ask whether it is possible to reconcile, what is sometimes perceived as, managerial Taylorism with the academic freedom of (Laurie) Taylorism. We conclude that recognition and active management of these processes are required for each university to optimise its own brand of core academic value
Evening choruses in the Perth Canyon and their potential link with Myctophidae fishes
An evening chorus centered at near 2.2 kHz was detected across the years 2000 to 2014 from seabed receivers in 430-490 m depth overlooking the Perth Canyon, Western Australia. The chorus reached a maximum level typically 2.1 h post-sunset and normally ran for 2.1 h (between 3 dB down points). It was present at lower levels across most of the hours of darkness. Maximum chorus spectrum levels were 74-76 dB re 1 µPa2/Hz in the 2 kHz 1/3 octave band, averaging 6-12 dB and up to 30 dB greater than pre-sunset levels. The chorus displayed highest levels over April to August each year with up to 10 dB differences between seasons. The spatial extent of the chorus was not determined but exceeded the sampling range of 13-15 km offshore from the 300 m depth contour and 33 km along the 300 m depth contour. The chorus comprised short damped pulses. The most likely chorus source is considered to be fishes of the family Myctophidae foraging in the water column. The large chorus spatial extent and its apparent correlation with regions of high productivity suggest it may act as an acoustic beacon to marine fauna indicating regions of high biomass
Environment change, economy change and reducing conflict at source
At a time when fossil fuel burning, nationalism, ethnic and religious intolerance, and other retrograde steps are being promoted, the prospects for world peace and environmental systems stability may appear dim. Yet now is it the more important to continue to examine the sources of conflict. A major obstacle to general progress is the currently dominant economic practice and theory, which is here called the economy-as-usual, or economics-as-usual, as appropriate. A special obstacle to constructive change is the language in which economic matters are usually discussed. This language is narrow, conservative, technical and often obscure. The rapid changes in the environment (physical and living) are largely kept in a separate compartment. If, however, the partition is removed, economics -as-usual, with its dependence on growth and its widening inequality, is seen to be unsustainable. Radical economic change, for better or worse, is to be expected. Such change is here called economy change. The change could be for the better if it involved an expansion of the concept of economics itself, along the lines of oikonomia, a modern revival of a classical Greek term for management or household. In such an expanded view, not everything of economic value can be measured. It is argued that economics-as-usual is the source of much strife. Some features are indicated of a less conflictual economy - more just, cooperative and peaceful. These features include a dignified life available to all people as of right, the word 'wealth' being reconnected with weal, well and well-being, and 'work' being understood as including all useful activity
Immunocompetent 3D Model of Human Upper Airway for Disease Modeling and In Vitro Drug Evaluation
The development of more complex in vitro models for the assessment of novel drugs and chemicals is needed because of the limited biological relevance of animal models to humans as well as ethical considerations. Although some human-cell-based assays exist, they are usually 2D, consist of single cell type, and have limited cellular and functional representation of the native tissue. In this study, we have used biomimetic porous electrospun scaffolds to develop an immunocompetent 3D model of the human respiratory tract comprised of three key cell types present in upper airway epithelium. The three cell types, namely, epithelial cells (providing a physical barrier), fibroblasts (extracellular matrix production), and dendritic cells (immune sensing), were initially grown on individual scaffolds and then assembled into the 3D multicell tissue model. The epithelial layer was cultured at the air–liquid interface for up to four weeks, leading to formation of a functional barrier as evidenced by an increase in transepithelial electrical resistance (TEER) and tight junction formation. The response of epithelial cells to allergen exposure was monitored by quantifying changes in TEER readings and by assessment of cellular tight junctions using immunostaining. It was found that epithelial cells cocultured with fibroblasts formed a functional epithelial barrier at a quicker rate than single cultures of epithelial cells and that the recovery from allergen exposure was also more rapid. Also, our data show that dendritic cells within this model remain viable and responsive to external stimulation as evidenced by their migration within the 3D construct in response to allergen challenge. This model provides an easy to assemble and physiologically relevant 3D model of human airway epithelium that can be used for studies aiming at better understanding lung biology, the cross-talk between immune cells, and airborne allergens and pathogens as well as drug delivery
Distinct Neurobehavioural Effects of Cannabidiol in Transmembrane Domain Neuregulin 1 Mutant Mice
The cannabis constituent cannabidiol (CBD) possesses anxiolytic and antipsychotic properties. We have previously shown that transmembrane domain neuregulin 1 mutant (Nrg1 TM HET) mice display altered neurobehavioural responses to the main psychoactive constituent of cannabis, Δ9-tetrahydrocannabinol. Here we investigated whether Nrg1 TM HET mice respond differently to CBD and whether CBD reverses schizophrenia-related phenotypes expressed by these mice. Adult male Nrg1 TM HET and wild type-like littermates (WT) received vehicle or CBD (1, 50 or 100 mg/kg i.p.) for 21 days. During treatment and 48 h after withdrawal we measured behaviour, whole blood CBD concentrations and autoradiographic receptor binding. Nrg1 HET mice displayed locomotor hyperactivity, PPI deficits and reduced 5-HT2A receptor binding density in the substantia nigra, but these phenotypes were not reversed by CBD. However, long-term CBD (50 and 100 mg/kg) selectively enhanced social interaction in Nrg1 TM HET mice. Furthermore, acute CBD (100 mg/kg) selectively increased PPI in Nrg1 TM HET mice, although tolerance to this effect was manifest upon repeated CBD administration. Long-term CBD (50 mg/kg) also selectively increased GABAA receptor binding in the granular retrosplenial cortex in Nrg1 TM HET mice and reduced 5-HT2A binding in the substantia nigra in WT mice. Nrg1 appears necessary for CBD-induced anxiolysis since only WT mice developed decreased anxiety-related behaviour with repeated CBD treatment. Altered pharmacokinetics in mutant mice could not explain our findings since no genotype differences existed in CBD blood concentrations. Here we demonstrate that Nrg1 modulates acute and long-term neurobehavioural effects of CBD, which does not reverse the schizophrenia-relevant phenotypes
Prospect theory, mitigation and adaptation to climate change
Climate change is one of the most pressing challenges in current environmental policy. Appropriate policies intended to stimulate efficient adaptation and mitigation should not exclusively rely on the assumption of the homo oeconomicus, but take advantage of well-researched alternative behavioural patterns. Prospect theory provides a number of climate-relevant insights, such as the notion that evaluations of outcomes are reference dependent, and the relevance of perceived certainty of outcomes. This paper systematically reviews what prospect theory can offer to analyse mitigation and adaptation. It is shown that accounting for reference dependence and certainty effects contributes to a better understanding of some well-known puzzles in the climate debate, including (but not limited to) the different uptake of mitigation and adaptation amongst individuals and nations, the role of technical vs. financial adaptation, and the apparent preference for hard protection measures in coastal adaptation. Finally, concrete possibilities for empirical research on these effects are proposed
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